Have you purchased a CTS Turbo MK6 Gen 3 GLI downpipe and you want to add one of our High Flow Cats? This is exactly what you need to add a high flow cat to your CTS-EXH-DP-0013 MK6 Gen 3 GLI Downpipe. If you have a complete turbo-back system from CTS Turbo and want to add a high flow cat choose that in the drop-down menu.